This is the website/blog of Philosopher Stephen Law. Stephen is Provost of Centre for Inquiry UK, Senior Lecturer in philosophy at Heythrop College, University of London, and editor of the Royal Institute of Philosophy journal THINK. He has published several books (see sidebar). His other blog is THE OUTER LIMITS: http://www.centerforinquiry.net/blogs/blibnblob
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Sunday, May 31, 2009

Can Your Prove God Doesn't Exist?

Austin Dacey and William Lane Craig talking about proving God does or doesn't exist.

If you are familiar with this blog, you will know I think we can prove beyond reasonable doubt that there is no God just by appeal to empirical evidence (and I also think it is possible to prove there is no God by conceptual means). See The God of Eth.

Incidentally, I think maybe Dacey at the beginning misses out a third kind of proof that X does not exist. He mentions:

(i) conceptual proofs(ii) proofs based on looking for a thing and failing to find it (note this seems to require X be observable, which God supposedly isn't)

But there is also this method:

(iii) show that if there were an X, there would not be Y (Y being observable). Y is observed to exist. Therefore X does not exist.

Note that (ii) takes absence of evidence to be (under certain circumstances) evidence of absence, whereas (iii) does not. My God of Eth "proof" is of the third kind.

P.S. Perhaps (ii) should also include: if there is an X, there would be Y (observable). Y is not observed. Therefore X does not exist. This does not require God be observable (as Dacey's formulation seems to require). But it is not as effective as (iii), as one might insist that our failure to observe Y does not show Y does not exist (again, we are still treating absence of evidence as evidence of absence). However, if Y were something that would be observable everywhere if God existed, such as "an absence of gratuitous evil", then the observation that there is no absence of gratuitous evil round here would directly entail there's no God. (iii) thus becomes a variant of (ii) after all.

14 comments:

We have to agree what we mean by "God" before we can confirm or disprove his/her/its existence. When we discuss the existence or non-existence of Zeus or Thor or Jehovah, we're discussing specific deities described in specific historical writings. There are good reasons to believe all those gods are false. But there are weaker forms of deism, which merely claim there is a higher force, more like gravity than like Krishna. Disproving that is more or less impossible.

Just suppose this is true. Our entire universe exists inside inside another universe, created by beings of that other universe. They've chosen the initial conditions of our universe, and its natural laws, based on what's most likely to lead to sentient self-aware life forms. But once our universe starts, they're powerless to intervene. Are they gods?

Why are you able to say that beings in the bigger universe are not supernatural?

FWIW I tend to agree but a professional opinion would be interesting.

In case (ii) can we not take the evidence of absence to be quite strong under specific restrictions . e.g I cannot look for evidence of God everywhere but I could say be fairly definite He wasn't in a particular region of space and time?

Stephen, are you familiar with the Thomistic arguments for god's attributes? Almost everyone is familiar with his five ways (though almost everyone also misunderstands them), but few seem to be familiar with his rigorous arguments for god's attributes (see, for example, book one of the Summa Contra Gentiles, chapters 15 - 102). These positive arguments for god's attributes weaken your god of eth argument by disposing of the assumption that arguments for god's existence and for god's attributes are not logically connected. ("Yet most of the popular arguments for the existence of God allow us to deduce little if anything about his moral character.") A great contemporary introduction to Thomism is Ed Feser's 'The Last Superstition.' Feser points out the fact that you can't simply read Aquinas without understanding quite a bit about the metaphysical principles that underlie his arguments. Most modern misunderstandings of Aquinas result from just this failure.

As far as the Judeo-Christian God goes, he is a character in a collection of stories. And you could say the same for Krishna.

I think Karen Armstrong covers this best in her book The History of God, where she points out that some of the 'prophets' or writers projected onto God the same character dispositions that they themselves possessed, or reflected the issues that they were dealing with in their own lives. This is not a central theme in her book, by the way; she just gives a couple of examples. Though I have to admit it's a number of years since I read it, and I no longer have a copy.

But I don't believe this addresses the question of a metaphysical entity for want of a better term. There are many religions where God is not a 'Creator' but people still believe in a metaphysical realm, which we would call Heaven. I'm thinking of the Chinese concept of Tao for example, which seems to me to represent a perfect world not unlike Plato's. It's just that in the West, because of our Christian heritage, we give this world a persona, and call it God.

Here's an attempted proof of the non-existence of God I whipped up a while back. It has a bit of a Humean character. I'm sure nobody will find it compelling, but then does anybody find arguments for the existence of God compelling either? Hopefully, the argument is valid.

1. Nothing is demonstrable, unless the contrary is a contradiction.

2. Whatever we conceive as existent, we can also conceive as non existent.

3. Deductive arguments for the existence of God attempt to demonstrate the existence of God.

4. There is no contradiction in denying that God exists. This follows from 2.

5. Therefore, deductive arguments for the existence of God fail as demonstrations because if they were sound, they would necessarily follow and could not be denied without contradiction.

6. God’s existence is not necessary, this follows from 2, we can conceive God as not existing and 5, deductive arguments for the existence of God can be denied without contradiction.

Brian, just a quick comment: 4 can be denied to follow from 2. The proponent of a particular ontological argument can simply say "oh, you might be able to conceive that god does not exist, but that is because you simply do not properly see the logical contradiction in denying his existence."

Thanks Kosh. Those premises are more a direct attack on demonstrative arguments. The plan being to show that demonstrative arguments can be denied, which means that God doesn't necessarily exist. - If a demonstration succeeds, and you accept the premises, you can't deny it's conclusion without contradiction. - Then from this one can only say God can possibly exist (which is all that is left to you if can't demonstrate God's existence) which contradicts the assumption of any ontological argument that posits God necessarily exists. Meaning we must reject any such ontological argument. So, I don't deny that an ontological argument posits an necessarily existing God. Only that in no world can there be an instantiation of a necessarily existent God.

"P.S. Perhaps (ii) should also include: if there is an X, there would be Y (observable)."

But in the end, isn't that what ii really states. Think about it, when we say, "We observe X," aren't we really saying, "we perceive the effects of X." I don't actually "see" a tree, I perceive the visible light reflected off the tree. With a neutrino, I can neither see it nor can I see visible light reflected off of it. What I can observe is an electromagnetic radiation being detected on an instrument after it has interacted with another particle.

Therefore I think that, "if there is an X, there would be Y (observable)," is just a scientifically more precise statement of ii.

As for Georges' aliens or deistic gods who created the conditions for the Big Bang and then never interacted with the natural universe again, I use the probability analysis (as Stephen put it, beyond a reasonable doubt). The human brain can create a virtually innumerable group of entities and phenomena which can not be empirically tested.

Out of all of the ones it has invented to date, how many have been demonstrated?

Based on all probabilities, it is then reasonable to conclude that any hypothesis, that has no concrete evidence to support it and no way to falsify it, is in fact false (guess I really can't blame a unicorn for stealing socks out of my dryer).

So why does the existence of this god matter? I guess that if one can reasonably deny that it's possible for God to exist, it makes the case for belief being rational a lost cause. I guess then believers would become fideists anyway....

Of course, there's the intellectual challange that these arguments present. For some, it's fun to figure out if they work or not.